| 1. |
- Coda, S., et al.
(författare)
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Overview of the TCV tokamak program : Scientific progress and facility upgrades
- 2017
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Ingår i: Nuclear Fusion. - : Institute of Physics Publishing. - 0029-5515 .- 1741-4326. ; 57:10
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Tidskriftsartikel (refereegranskat)abstract
- The TCV tokamak is augmenting its unique historical capabilities (strong shaping, strong electron heating) with ion heating, additional electron heating compatible with high densities, and variable divertor geometry, in a multifaceted upgrade program designed to broaden its operational range without sacrificing its fundamental flexibility. The TCV program is rooted in a three-pronged approach aimed at ITER support, explorations towards DEMO, and fundamental research. A 1 MW, tangential neutral beam injector (NBI) was recently installed and promptly extended the TCV parameter range, with record ion temperatures and toroidal rotation velocities and measurable neutral-beam current drive. ITER-relevant scenario development has received particular attention, with strategies aimed at maximizing performance through optimized discharge trajectories to avoid MHD instabilities, such as peeling-ballooning and neoclassical tearing modes. Experiments on exhaust physics have focused particularly on detachment, a necessary step to a DEMO reactor, in a comprehensive set of conventional and advanced divertor concepts. The specific theoretical prediction of an enhanced radiation region between the two X-points in the low-field-side snowflake-minus configuration was experimentally confirmed. Fundamental investigations of the power decay length in the scrape-off layer (SOL) are progressing rapidly, again in widely varying configurations and in both D and He plasmas; in particular, the double decay length in L-mode limited plasmas was found to be replaced by a single length at high SOL resistivity. Experiments on disruption mitigation by massive gas injection and electron-cyclotron resonance heating (ECRH) have begun in earnest, in parallel with studies of runaway electron generation and control, in both stable and disruptive conditions; a quiescent runaway beam carrying the entire electrical current appears to develop in some cases. Developments in plasma control have benefited from progress in individual controller design and have evolved steadily towards controller integration, mostly within an environment supervised by a tokamak profile control simulator. TCV has demonstrated effective wall conditioning with ECRH in He in support of the preparations for JT-60SA operation.
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| 2. |
- Pattaro, Cristian, et al.
(författare)
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Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways.
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| 3. |
- Accomando, E., et al.
(författare)
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Physics with e + e - linear colliders
- 1998
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Ingår i: Physics Reports. - 0370-1573. ; 299:1, s. 1-78
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Tidskriftsartikel (refereegranskat)abstract
- The physics potential of e + e - linear colliders is summarized in this report. These machines are planned to operate in the first phase at a center-of-mass energy of 500 GeV, before being scaled up to about 1 TeV. In the second phase of the operation, a final energy of about 2 TeV is expected. The machines will allow us to perform precision tests of the heavy particles in the Standard Model, the top quark and the electroweak bosons. They are ideal facilities for exploring the properties of Higgs particles, in particular in the intermediate mass range. New vector bosons and novel matter particles in extended gauge theories can be searched for and studied thoroughly. The machines provide unique opportunities for the discovery of particles in supersymmetric extensions of the Standard Model, the spectrum of Higgs particles, the supersymmetric partners of the electroweak gauge and Higgs bosons, and of the matter particles. High precision analyses of their properties and interactions will allow for extrapolations to energy scales close to the Planck scale where gravity becomes significant. In alternative scenarios, i.e. compositeness models, novel matter particles and interactions can be discovered and investigated in the energy range above the existing colliders up to the TeV scale. Whatever scenario is realized in Nature, the discovery potential of e + e - linear colliders and the high precision with which the properties of particles and their interactions can be analyzed, define an exciting physics program complementary to hadron machines.
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| 4. |
- Norbury, John W., et al.
(författare)
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Are Further Cross Section Measurements Necessary for Space Radiation Protection or Ion Therapy Applications? Helium Projectiles
- 2020
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Ingår i: Frontiers in Physics. - : Frontiers Media SA. - 2296-424X. ; 8
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Forskningsöversikt (refereegranskat)abstract
- The helium ((Formula presented.) He) component of the primary particles in the galactic cosmic ray spectrum makes significant contributions to the total astronaut radiation exposure. (Formula presented.) He ions are also desirable for direct applications in ion therapy. They contribute smaller projectile fragmentation than carbon ((Formula presented.) C) ions and smaller lateral beam spreading than protons. Space radiation protection and ion therapy applications need reliable nuclear reaction models and transport codes for energetic particles in matter. Neutrons and light ions ((Formula presented.) H, (Formula presented.) H, (Formula presented.) H, (Formula presented.) He, and (Formula presented.) He) are the most important secondary particles produced in space radiation and ion therapy nuclear reactions; these particles penetrate deeply and make large contributions to dose equivalent. Since neutrons and light ions may scatter at large angles, double differential cross sections are required by transport codes that propagate radiation fields through radiation shielding and human tissue. This work will review the importance of (Formula presented.) He projectiles to space radiation and ion therapy, and outline the present status of neutron and light ion production cross section measurements and modeling, with recommendations for future needs.
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| 5. |
- Fuks, Kateryna B., et al.
(författare)
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Arterial blood pressure and long-term exposure to traffic-related air pollution : an analysis in the European Study of Cohorts for Air Pollution Effects (ESCAPE)
- 2014
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Ingår i: Journal of Environmental Health Perspectives. - : National Institute of Environmental Health Sciences (NIEHS). - 0091-6765 .- 1552-9924. ; 122:9, s. 896-905
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Forskningsöversikt (refereegranskat)abstract
- BACKGROUND: Long-term exposure to air pollution is hypothesized to elevate arterial blood pressure (BP). The existing evidence is scarce and country-specific. OBJECTIVES: We investigated the cross-sectional association of long-term traffic-related air pollution with BP and prevalent hypertension in European populations. METHODS: Fifteen population-based cohorts, participating in the European Study of Cohorts for Air Pollution Effects (ESCAPE), were analysed. Residential exposure to particulate matter and nitrogen oxides was modelled with land use regression using a uniform protocol. Traffic exposure was assessed with traffic indicator variables. We analysed systolic and diastolic BP in participants medicated and non-medicated with BP lowering medication (BPLM) separately, adjusting for personal and area-level risk factors and environmental noise. Prevalent hypertension was defined as ≥ 140 mmHg systolic, or ≥ 90 mmHg diastolic BP, or intake of BPLM. We combined cohort-specific results using random-effects meta-analysis. RESULTS: In the main meta-analysis of 113,926 participants, traffic load on major roads within 100 m of the residence was associated with increased systolic and diastolic BP in non-medicated participants (0.35 mmHg [95% CI: 0.02-0.68] and 0.22 mmHg [95% CI: 0.04-0.40] per 4,000,000 vehicles × m/day, respectively). The estimated odds ratio for prevalent hypertension was 1.05 [95% CI: 0.99-1.11] per 4,000,000 vehicles × m/day. Modelled air pollutants and BP were not clearly associated. CONCLUSIONS: In this first comprehensive meta-analysis of European population-based cohorts we observed a weak positive association of high residential traffic exposure with BP in non-medicated participants, and an elevated OR for prevalent hypertension. The relationship of modelled air pollutants with BP was inconsistent.
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| 6. |
- Gault, Baptiste, et al.
(författare)
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Towards Establishing Best Practice in the Analysis of Hydrogen and Deuterium by Atom Probe Tomography
- 2024
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Ingår i: Microscopy and Microanalysis. - 1435-8115 .- 1431-9276. ; In Press
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Forskningsöversikt (refereegranskat)abstract
- As hydrogen is touted as a key player in the decarbonization of modern society, it is critical to enable quantitative hydrogen (H) analysis at high spatial resolution and, if possible, at the atomic scale. H has a known deleterious impact on the mechanical properties (strength, ductility, toughness) of most materials that can hinder their use as part of the infrastructure of a hydrogen-based economy. Enabling H mapping including local hydrogen concentration analyses at specific microstructural features is essential for understanding the multiple ways that H affect the properties of materials including embrittlement mechanisms and their synergies. In addition, spatial mapping and quantification of hydrogen isotopes is essential to accurately predict tritium inventory of future fusion power plants thus ensuring their safe and efficient operation. Atom probe tomography (APT) has the intrinsic capability to detect H and deuterium (D), and in principle the capacity for performing quantitative mapping of H within a material's microstructure. Yet, the accuracy and precision of H analysis by APT remain affected by complex field evaporation behavior and the influence of residual hydrogen from the ultrahigh vacuum chamber that can obscure the signal of H from within the material. The present article reports a summary of discussions at a focused workshop held at the Max-Planck Institute for Sustainable Materials in April 2024. The workshop was organized to pave the way to establishing best practices in reporting APT data for the analysis of H. We first summarize the key aspects of the intricacies of H analysis by APT and then propose a path for better reporting of the relevant data to support interpretation of APT-based H analysis in materials.
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